SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e36f03503c9d662940f0aa4317fe944ed0d3017653b05c752b32b2aed6ae23e1' 
  AND token = '9eMgpzu15+sB+kbNfxr6yLIDkfBCyMGU0Yn7FtEGkJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}